Hebrews 9:15

For this reason He is the Mediator and Negotiator of a new covenant (that is, an entirely new agreement uniting God and man, so that those who have been called (by God) may receive (the fulfillment of) the promised eternal inheritance, since a death has taken place (as the payment) which redeems them from the sins committed under the obsolete covenant.  

Under the old covenant, blood had to be shed every year for the sins of the people.  Jesus shed His blood once and for all for sin, creating a better covenant.  Jesus breached the gulf between God and man-made at the fall with Adam.  Jesus took back the keys of death and restored eternal life as God had promised.